As a kid, I spent my summers with my grandparents on the ranch（大农场） in Texas（德克萨斯州（美国州名））. I helped fix windmills（风车）, vaccinate（接种疫苗） cattle（牛）, and do other chores（杂务）. We also watched soap operas（歌剧） every afternoon, especially days of our lives. My grandparents belonged to a caravan（（可供居住的）拖车） club, a group of Airstream（气流） trailer（追踪者） owners who traveled together around the US and Canada. And every few summers, we'd join the caravan. We'd hitch（搭便车） up the Airstream（气流） to my grandfather's car, and off we'd go.

  In a line with 300 other Airstream adventurers（冒险者）, I loved and worshiped（崇拜） my grandparents. And I really looked forward to these trips. On one particular trip, I was about 10 years old. I was rolling around in the big bench（长凳） seat in the back of the car. My grandfather was driving, and my grandmother had the passenger seat. She smoked throughout these trips, and I hated the smell.

  At that age, I'd take any excuse（借口） to make（使） estimates（估计） and do minor arithmetic. I'd calculate（计算） our gas mileage, figure（ 认为） out useless（ 无用的） statistics on things like grocery（食品杂货店） spending. I'd been hearing an ad campaign about smoking. I can't remember the details, but basically（基本上） the ad said, every puff（粉扑） of a cigarette takes some number of minutes off of your life. I think it might have been two minutes per puff. At any rate, I decided to do the math for my grandmother.

  I estimated the number of cigarettes per day, estimated the number of puffs per cigarette, and so on. When I was satisfied（感到满意的） that I'd come up with a reasonable（合理的） number, I poked（ 刺） my head into the front of the car, tapped（轻敲） my grandmother on the shoulder, and proudly（傲慢地） proclaimed（宣告）, "At two minutes per puff（粉扑）, you've taken nine years off of your life." I have a very vivid memory of what happened next, and it was not what I had expected. I expected to be applauded（ 鼓掌） for my cleverness（聪明） and my arithmetic skills. "Jeff, you're so smart, you had to have made some tricky（ 狡猾的） estimates（估计）, figure out the number of minutes in a year, and do some division（[数] 除法）." That's not what happened.

  Instead, my grandmother burst（使爆裂） into tears（ 眼泪）. I sat in the back seat, didn't know what to do, while my grandmother was crying. My grandfather, who'd been driving in silence（沉默）, pulled over onto the shoulder of the highway（公路）. He got out of the car and came around and opened my door and waited for me to follow. Was I in trouble? My grandfather was a highly intelligent, quiet man.

  He had never said a harsh（严厉的） word to me, and maybe this was to be the first time.